Polyvinylchloride (PVC) is the accepted material for use as tubing in various medical applications, such as peritoneal dialysis, blood processing, chemotherapy and other uses. In such uses, a consumable is conveyed through the tubing from one location to another. For peritoneal dialysis (CAPD), for example, it is also the practice to replace a used dialysate bag with a new bag. This is accomplished by cutting through the PVC tubing leading from the used bag and then welding tubing from a new bag to the cut portion of the tubing so that one bag may replace another. PVC is also the generally accepted material for forming bags and other medical containers and is commonly used as tubing in food processing particularly for fluids and semi-solids. In addition, PVC is the material generally used for forming sheets and films for bacterial and virus exclusion. Despite its acceptance by the art, PVC has a number of disadvantages which would be desirable to overcome in such uses. For example, conventional PVC includes a plasticizer (DOP) which might leach into the solutions in the bag. Further, after PVC has leached its DOP, large volumes of PVC particulates are released. Other disadvantages will be later referred to.
U.S. Pat. No. 4,048,254 (Hillier) and U.S. Pat. No. 4,816,343 (Mueller) disclose materials intended to replace PVC. U.S. Pat. No. 4,670,510 (Kobayashi) discloses polyester block copolymer compositions having rubber-like elasticity. Such compositions includes polyester ethers.
An object of this invention is to provide a material which will act as an improved replacement for PVC in the conventional uses of PVC.
A further object of this invention is to provide such a material which can be used as tubing for medical applications, as bags and other medical containers, for tubing food processing and as sheets and films for bacterial and virus exclusion.
In accordance with this invention the material which meets the above objects is an ionomeric modified poly-ether-ester. The ionomeric modifier is added in a range of 1% to 20% depending upon the end use requirement.